[Question] PCI ACS is broken for ARM SMMU v3?
From: wangzhou1@hisilicon.com (Zhou Wang)
Date: 2017-09-04 12:33:22
Also in:
linux-pci
From: wangzhou1@hisilicon.com (Zhou Wang)
Date: 2017-09-04 12:33:22
Also in:
linux-pci
+to: Lorenzo On 2017/8/31 22:21, Zhou Wang wrote:
Hi Will and Alex, pci_request_acs is called in drivers/iommu/arm-smmu-v3.c to set pci_acs_enable. PCI subsystem tries to enable ACS as below: pci_device_add --> pci_init_capabilities --> pci_enable_acs in ACPI PCI driver. However, ACPI PCI driver will be called before SMMU v3 driver, which will lead pci_enable_acs to return directly as pci_acs_enable is not set before SMMU v3 driver loading. I think this is a bug, what do you think about this problem? Best, Zhou .